Effects of continuous low frequency noise on the emotion and behavior of rats / 第二军医大学学报

ABSTRACT

Objective To explore the effects of continuous low frequency noise on the emotion and behavior of rats. Methods Forty rats were randomly divided into normal control (NC) group and noise exposure(NE) group, with 20 rats in each group. Rats in NE group were exposed to 100 Hz, 70 dB noise for 1 hour at early, middle and late time of the day in a daily manner for 8 weeks. Rats in NC group were raised in normal background noise in an environment with a noise less than 40 dB. The body mass measurement, sucrose preference test, handling test and open field test were done to evaluate the emotion and behavior of rats at the beginning and 2, 4, 6, 8 weeks of experiment. Results (1)The body mass change trends were significant between the two groups at different time points(P<0.05). The body mass gain of rats in NE group was greatly less than that of the NC rats. (2)Regardless of the impact of time, the main effects in sucrose preference test were significantly different between the two groups (P<0.01). The change trends of sucrose preference were significantly different between the two groups at different time points(P<0.05), with the percentage of sucrose preference of NE rats greatly decreased with time. (3) The tension stimulation score and pain score of handling test in NE rats were significantly higher than those in NC rats(P<0.05 or P<0.01). (4) The horizontal and vertical movement abilities in NE rats were significantly decreased with the noise exposure period compared with the control group; the effects of time, groups and interaction were all significantly different (Pnoise can lead to decrease of body weight and movement ability of rats, accompanied by emotional reactions such as anxiety and depression, and the severities of the changes are closely related to exposure time.